Judicial review is a way of making sure that public officials, including ministers, keep within the law. Strictly speaking, it is a remedy rather than a process: lawyers speak of claimants "seeking judicial review" of a decision and it is something of a solecism to describe an application itself as "a judicial review" — although that usage is now widely accepted. Applications are made to the Administrative Court, which is part of the High Court and has an inherent supervisory jurisdiction to ensure that public bodies operate within their powers and in accordance with the law. To that end, the court can quash a decision if the claimant can establish what's described as illegality, irrationality or procedural impropriety.

Last November, David Cameron made a speech to the Confederation of British Industry in which he promised to abolish unnecessary restraints on businesses, describing judicial review as a "massive growth industry" that the government needed urgently "to get a grip on".

For two reasons, it was a curious audience for the prime minister to choose. First, as he had the grace to accept, an application for judicial review brought recently by a large business — Virgin Rail — had forced the Department for Transport to concede that there had been "significant technical flaws" in the competition for the lucrative West Coast main line, under which Virgin would have lost its franchise. The cost to taxpayers of cancelling the winner's contract is estimated to be £40 million — although the cost to British businesses of giving the franchise to a company with inadequate resources would presumably have been much higher.

The second reason is that judicial review is not much of a problem for British business. As the government conceded in a subsequent consultation paper, the increase in applications has "mainly been the result of the growth in the number of challenges made in immigration and asylum matters". In 2011, "these represented over three-quarters of all applications for permission to apply for judicial review". Permission was refused in five cases out of six. And the Crime and Courts Bill, which is nearly through parliament, will soon transfer these cases from the High Court to specialist tribunal judges. That will make a "huge difference", according to the Lord Chief Justice.

Even so, the government is concerned at the delay in weeding out hopeless cases. There is also concern that fear of judicial review is making public bodies over-cautious.